refactor: ByteOffset newtype for window/register/ring offsets; named virtio-gpu cmd fields

crates/init/src/selftest.rs

@@ -68,7 +68,7 @@ fn check_stopped(words: Words, what: &'static str) -> Result<(), &'static str> {
 fn run_phases(storage: &mut Storage, scratch: &mut [u8]) -> Result<(), &'static str> {
     let page = syscall::create_region(PageCount::new(1).ok_or("page count")?).map_err(|_| "no counter page")?;
     let window = libkos::window::map(page, OBSERVE_VA, PagePerms::ReadWrite).map_err(|_| "cannot map the counter page")?;
-    let words = window.atomics(0, 1 + THREADS);
+    let words = window.atomics(types::address::ByteOffset::ZERO, 1 + THREADS);
 
     let events = syscall::create_notification().map_err(|_| "no notification")?;
     timer_is_on_time(events)?;